2-DIMENSIONAL ELECTRON GASES IN THE QUANTUM HALL REGIME - ANALYSIS OFTHE CIRCULATING CURRENT IN CONTACTLESS CORBINO GEOMETRY

We have investigated the magnitude of the circulating bulk current den sity in Corbino geometry with high-impedance capacitive contacts using : a two-dimensional distributed model. For parameters suited for GaAlA s/GaAs heterostructure samples we find that local current densities ca n attain values larger than 1 A/m, at which a breakdown of the quantum Hall effect might be expected. The circulating current is found to be sufficiently large to allow inductive detection, and we suggest this as a method to measure sigma(xy). Copyright (C) 1996 Elsevier Science Ltd